rust/library/std/src/sys, branch try

Rollup merge of #143592 - ChrisDenton:uwp-link, r=Mark-Simulacrum

2025-07-17T01:58:29+00:00

UWP: link ntdll functions using raw-dylib Lazy loading isn't necessary so there's no need for the added complexity and overhead. However, it may be that people using UWP rust libraries don't have the necessary import libraries linked by Visual Studio so this uses raw-dylib, which allows linking to DLL functions without having an import library. This is a somewhat temporary situation as raw-dylib is intended to eventually be the default for all imports. When that happens, this special case can be removed. Closes rust-lang/rust#143530

Rollup merge of #143910 - ChrisDenton:no-symbolization, r=tgross35

2025-07-15T10:52:42+00:00

Add experimental `backtrace-trace-only` std feature This experimentally allows building std with backtrace but without symbolisation. It does not affect stable and requires build-std to use. This doesn't change the backtrace crate itself so relies on the optimizer to remove the unused parts. Example usage: ```toml # .cargo/config.toml [unstable] build-std = ["core", "alloc", "panic_unwind", "std"] build-std-features = ["backtrace", "backtrace-trace-only", "panic-unwind"] ``` ```toml # Cargo.toml [profile.release] opt-level = 3 lto = "thin" codegen-units = 1 ``` Ideally we should split the backtrace feature into `backtrace-trace` and `backtrace-symbolize` (with the latter dependent on the former) because Cargo features tend to work better when they're positive rather than negative. But I'm keen for this experiment not to break existing users. cc ``@joshtriplett``

Rollup merge of #143710 - joshtriplett:random-updates, r=joshtriplett

2025-07-14T16:05:44+00:00

Updates to random number generation APIs Updates based on discussions about random number generation. - Add comment on `RandomSource::fill_bytes` about multiple calls, to allow efficient implementations for random sources that generate a word at a time. - Drop the `Random` trait in favor of `Distribution`, which will let people make calls like random(1..=6), and which allows for future expansion to non-uniform distributions, as well as floating-point. (For now, this is only implemented for `RangeFull`, to get the interface in place. Subsequent PRs will implement it for other range types.)

Rollup merge of #141809 - ChrisDenton:no-cleaup, r=jhpratt

2025-07-14T16:05:43+00:00

Don't call WSACleanup on process exit This isn't necessary as cleanup will happen when the process exits regardless. fixes rust-lang/rust#141799

Don't call WSACleanup on process exit

2025-07-14T14:27:49+00:00

Add experimental backtrace-trace-only std feature

2025-07-14T11:52:17+00:00

Rollup merge of #143881 - orlp:once-state-repr, r=tgross35

2025-07-14T09:04:55+00:00

Use zero for initialized Once state By re-labeling which integer represents which internal state for `Once` we can ensure that the initialized state is the all-zero state. This is beneficial because some CPU architectures (such as Arm) have specialized instructions to specifically branch on non-zero, and checking for the initialized state is by far the most important operation. As an example, take this: ```rust use std::sync::atomic::{AtomicU32, Ordering}; const INIT: u32 = 3; #[inline(never)] #[cold] pub fn slow(state: &AtomicU32) { state.store(INIT, Ordering::Release); } pub fn ensure_init(state: &AtomicU32) { if state.load(Ordering::Acquire) != INIT { slow(state) } } ``` If `INIT` is 3 (as is currently the state for `Once`), we see the following assembly on `aarch64-apple-darwin`: ```asm example::ensure_init::h332061368366e313: ldapr w8, [x0] cmp w8, #3 b.ne LBB1_2 ret LBB1_2: b example::slow::ha042bd6a4f33724e ``` By changing the `INIT` state to zero we get the following: ```asm example::ensure_init::h332061368366e313: ldapr w8, [x0] cbnz w8, LBB1_2 ret LBB1_2: b example::slow::ha042bd6a4f33724e ``` So this PR saves 1 instruction every time a `LazyLock` gets accessed on platforms such as these.

Add comment why we use zero for COMPLETE

2025-07-13T10:37:34+00:00

Use zero for initialized Once state

2025-07-13T10:16:40+00:00

Attempt to fix up SGX for random API updates

2025-07-13T09:54:27+00:00